“Aquinas can’t actually be a Catholic can he? Most of his ideas are from that Pagan, Aristotle!”
The Genetic Fallacy, or the Fallacy of Origins, is a fallacy of irrelevance where we try and dismiss the impact of the argument by showing how it came to be. In most cases, this is a form of emotional non-sequitor intended to undercut a conclusion by attacking the character of the speaker, but it can also be used in a historical sense.
In the first sense, the emotional trick of trying to call the source into question would look something like this, “You heard that the sky was blue from who? Your mother, the blind woman?” By citing that his mother was blind and could not have seen the sky, calls into question the statement ‘the sky is blue’ without actually giving any argument.
The second version looks a bit more educated, but is still a fallacy: For example, if arguing about whether someone has arrived yet.
“Has he arrived yet?”
“No! He came by car, not by boat!”
This example does not appear at all educated, but if it were to be revised in such a manner…
“He has not arrived because in order for him to arrive he must come by boat. The reasoning for this is that “arrive” is derived from “a” + “ripa” which means ‘from, by, since, or of’ and ‘the shore’ in Latin. Thus, since there is no shore line, nor even any boats, he could never have arrived, since he is not coming ‘of the shore.'”
This is at the very least factually correct, however incorrect in it’s usage. The modern word ‘arrive’ does not mean anything like that, though it is easy to see how it got it’s meaning from that. So appeals to the origin to undermine a conclusion are fallacious.
…most of the time.
This would be a simple matter, if any time anyone made an origin appeal we could simply say “A-ha! Genetic fallacy! Stop right there!” But it is unfortunately, not that easy. The Genetic Fallacy is only a fallacy if and only if the only reason you have for dismissing the conclusion is its origins.
Let us see if we can find an example of an origin appeal that is not fallacious.
N as naturalism, which he defined as “the idea that there is no such person as God or anything like God; we might think of it as high-octane atheism or perhaps atheism-plus.”
E as the belief that human beings have evolved in conformity with current evolutionary theory
R as the proposition that our faculties are “reliable”, where, roughly, a cognitive faculty is “reliable” if the great bulk of its deliverances are true. He specifically cited the example of a thermometer stuck at 72 °F (22 °C) placed in an environment which happened to be at 72 °F as an example of something that is not “reliable” in this sense
and suggested that the conditional probability of R given N and E, or P(R|N&E), is low or inscrutable. (1)
Plantinga is not suggesting that because faculties evolved out of atoms they must be false, but rather his argument is based on a distinction between “belief” and “behavior”. Natural selection only wants us to survive, and so could very well give us useful beliefs that are fiction. If we need to run away from Tigers in order to survive, then we could have the conjunction of beliefs “I want to pet the kitty” and “The best way to pet cats is to run away from them.” resulting in our survival.
Say what you want about this argument, I haven’t done a lot of research into it myself, but it is not an example of the genetic fallacy due to the fact that the origins are called into doubt due to external argument that relates it to the topic at hand(namely, the reliability of our faculties)
So: Three things to check for when looking for the Genetic Fallacy.
1. An undermining of the conclusion based on it’s origin(either historically or personally or linguistically or whatever.)
2. No external argument to support the initial claim.
3. Relevance to the issue at hand. If the argument does not relate at all to the topic at hand, such as the “A”+”Ripa” example I gave(which is a complete non-sequitor) chances are you have a Genetic Fallacy.
Genetic fallacies also do not necessarily mean that the proposition is false.
“The world is round, I read it in this week’s Batman.
“Well you read that in a comic book so it cannot be true, because men don’t fly.”
This is an example where the proposition proposed is true, but the origin has only a personal effect on the speaker, not on the proposition. In reality, this fallacy is one of irrelevance. If it can be shown to be even remotely related to the conclusion it is trying to undermine and the argument it is couched in, then you do not have the genetic fallacy.
(1) Copied from Wikipedia article on “The Evolutionary Argument Against Naturalism” Mostly because I was too lazy to type out this example.